1. Field of the Invention
The present invention relates to a modular jack, and more particularly to a modular jack having improved magnetic module efficiently eliminating electromagnetic interference to signal.
2. Description of Prior Arts
U.S. Pat. No. 5,736,910 issued to Townsend et al on Apr. 7, 1998 discloses a modular jack mounted onto a mother printed circuit board and adapted for receiving a plug. The modular jack includes a housing defining a receptacle, a daughter printed circuit board attached to a rear portion of the housing, a first set of contacts mounted to the housing for engaging with the plug and a second set of contacts assembled to the printed circuit board for connecting to the mother printed circuit board. A plurality of groups of toroidal coil pairs are interposed between the first contacts and the second contacts for eliminating high frequency noise. Each toroidal coil pair has a first toroidal core performing as a common mode filter, a second toroidal core performing as a transformer. Each toroidal coil pair has at least a coil wound around the first toroidal core and the second toroidal core for electrically connecting the first core and the second toroidal cores together.
U.S. Pat. No. 5,069,641 issued to Sakamoto et al. discloses a modular jack to be mounted on an outer circuit board. The modular jack has a printed circuit board having a noise suppressing electronic element received in a housing. The printed circuit board is fitted with contacts for contacting with plugs and terminals to mount the modular jack on the outer circuit board. The contacts and the terminals are electrically connected with the noise suppressing electronic element by wires on the printed circuit board.
In general, it needs more space for locating such a large number of the toroidal coil pairs between the first and the second set of contacts, which increase the cost of manufacture.
Hence, it is desirable to provide an improved modular jack to overcome the aforementioned disadvantages.